Wisconsin Democrats are already lining up to replace Rep. Tammy Baldwin (D) should she leave her 2nd district seat to run for the Senate.

State Rep. Kelda Roys, leader of the House Democratic Caucus, told Roll Call that she's considering a run should the seat become vacant.

"This is all very dependent on what Rep. Baldwin decides to do. I'm definitely giving it serious consideration, so if the time comes when she declares, I'll be able to hit the ground running," Roys said.

Baldwin is largely expected to seek the Senate seat held by retiring Sen. Herb Kohl (D) in 2012. She currently represents the state's most Democratic district, which President Barack Obama won by 39 points in 2008.

Roys is just one of many of Democrats expected to compete in a primary. State Sen. Jon Erpenbach and state Rep. Mark Pocan are also names to watch.

"There may be other people popping out of the woodwork who will consider running," Roys said, declining to put a timetable on her decision.

Roys was first elected to the state Legislature in 2008. Just 31 years old, she is an attorney and former executive director of NARAL Pro-Choice Wisconsin.